In the field of paper crafting, pieces of paper or cardboard of various shapes are punched out from sheets of paper or cardboard by paper punches. A conventional paper punch is shown in FIGS. 1 and 2 and generally designated as 10. The paper punch 10 has a operating handle 12 operatively associated with a main body 14. A generally horizontal slot 16 is provided in the main body 14, for insertion of a sheet of paper or cardboard 18. The operating handle 12 may then be pivoted downwardly to move a punch die (see FIG. 4) to punch or cut out a piece of shaped paper or cardboard 18a from the piece of paper or cardboard 18, as shown in FIG. 3.
As shown in FIG. 4, the operating handle 12 is pivotable about a point 20 to bear down on a metal punch die 22 to move vertically downward to pass through a slot 24 between an upper jaw 26 and a lower jaw 28 of a metal base 30 to perform the cutting action. Upon release of the downward force, a spring 32 provided between the punch die 22 and the base 30 acts to return the punch die 22 to the upper stable position as shown in FIG. 4.
In a conventional paper punch, the die and the die holder (also called a “base”) are made of metal or metal alloy (such as copper, aluminium, silver, zinc or tin) by low pressure die cast, e.g. by injection molding. Although it has been known that the cost of the product may be reduced if at least part of the die or base is made of a plastics material, it has long, been held by people in the field that such may jeopardize proper alignment between the die and the base, in particular during the course of relative movement between the die and the base in the punching action. It is also believed that the strength and rigidity of the base may be compromised if part of it is made of other materials, e.g. a plastics material.
It is thus an object of the present invention to provide a base for a paper punch, a paper punch with such a base, and a method of forming such a base in which at least part of the base is made of a plastics material, while minimizing the aforesaid envisaged shortcomings, or at least to provide a useful alternative to the trade and public.